.photo {
    float: left;
    width: 25%; 
    padding: 0px; 
    box-sizing: border-box; 
}
.photo img {
    display: block;
    max-width: 100%;
    height: auto;
   
}

.photo figcaption {
    font-family: sans-serif;
    color: #999999;
    text-align: center;
    margin-top: 10px;
}

#gallery {
    margin-bottom: 15px;
}

#gallery:after { 
   content: '';
   display: block; 
   height: 0; 
   clear: both;
}